Sri Lanka’s parliament has passed a no-confidence motion against the country’s purported prime minister Mahinda Rajapaksa, according to opposition lawmakers, deepening the political crisis gripping the country.

There were chaotic scenes on the floor of the country’s parliament for the vote on Wednesday morning, with reports Rajapaksa stormed out of the house and that some legislators from his party tried to halt the vote.

At least four lawmakers have said the parliamentary speaker, Karu Jayasuriya, took a voice vote and declared Rajapaksa’s government had no majority – effectively dissolving it.

But it is unclear if Rajapaksa and his allies accept the result. One supporter, Anura Priyadarsjana Yapa, said his side had no opportunity to see the no-confidence motion and that according to parliamentary rules they need five days’ notice for the vote.

Parliament has been adjourned until 10am on Thursday, but there are fears the assembly could be suspended before then.

At least five MPs who had previous expressed support for Rajapaksa crossed over on Wednesday morning to his opponent, Ranil Wickremesinghe.

Both men claim to be the lawful prime minister. The country’s president, Maithripala Sirisena, has been trying to sack Wickremesinghe and replace him with Rajapaksa.